Patent GB-519396-A (GB)
Title: Improvements relating to turret lathes
IPC: B23B7/04
Filed: 1938-10-21
Abstract: 519,396. Lathes. SCHAERER, O. Oct. 21, 1938, No. 30531. Convention date, Oct. 23, 1937. [Class 83 (iii)] Turret lathes, for barstock of the type having a turret rotatable about a shaft parallel to and to one side of the spindle, a longitudinally fed tool slide, a cross slide, and preferably a boring slide that may serve also as a tailstock, have the turret 56 splined to slide on a sleeve 60,surrounding its shaft and connected to the indexing mechanism. The index plate 92, Fig. 2, is secured to the sleeve and is rotated through one sixth of a revolution by a rotating arm 87 which also carries a cam 86 for releasing the index bolt 90 through a lever 89. The arm 87 is carried by a shaft 85 driven through a clutch 82, Fig. 8, toothed gearing 84 and a yielding friction clutch 77 from a constant speed shaft 14 rotated continuously by a motor-driven pulley 11, the clutch 82 being normally held open by a cambar 80. When the turret is returned to inoperative position, guide rods 52, 55, Fig. 5, carried by a disc 57 rotatable on the turret, act as a stop spindle 74 through a yoke '54 to cause a cam surface on the spindle to release the bar 80 and allow the clutch 82 to engage. After one revolution of the shaft 85 the clutch engages the bar 80 to cam itself open. The turret is fed in the working direction by a pinion 51 engaging a rack on the rod 52 and driven through bevel gears 49, a transverse shaft 48, Fig. 4, a yielding clutch 47, a worm drive 44, a change-speed gear controlled by 'a handle 135, and a shaft 42, Fig. 8, driven from the work-spindle 8. At the end of a working stroke of the turret, a pin 62 on the yoke 54 engages a dog 63 on a selector stop bar 65 to move the bar axially and disengage the feed clutch 47 through a lever 68, and rods and levers 69, 70, 71. The turret is returned to inoperative position by a hand wheel 72 on the shaft 48, which may also be used for hand feeding. The selector bar 65 is indexed together with the turret by gearing 97. The boring slide 3, Fig. 4, is clamped to the bed 7 by an eccentric and handle 101 and carries a sliding tool spindle 118 fed forwards by a rack whose pinion 116 Fig. 4, is driven by a shaft 110, change-feed gears in a bore 103, clutch 112, worm gear 108, and chain drive 102 from the shaft 44. At the end of the boring stroke a collar on the spindle 118 engages a spring stop bar to disengage the clutch 112, after which the spindle is returned by a hand wheel 124 on the shaft 110. An angle bar 129 on each face of the turret 56 engages the spindle 118 on the return stroke to withdraw the spindle and prevent interference by the turret tools. The boring slide 3 also carries a bar-feed stop 125 rotatable about an axially adjustable rod 127. The cross slide 4, Fig. 2, which carries a cutting-off tool, is fed by a rackpinion rotated by a hand lever 131, or may be fed automatically. The lathe spindle 8, Fig. 8, is driven from the pulley 11 by the change gears and clutches shown, pick-off gears 31 and reversing gears 22 so that it may be rotated at four forward or two reverse speeds without altering the pick-off gears. The bar feed through the spindle is driven at 37 from the spindle.